THE DIS­AS­TER-PROOF IN­TER­NET

The earth­quake in Iran, Hur­ri­cane Irma in Puerto Rico, Cal­i­for­nia wild­fires. As vi­tal as food and clean wa­ter, catas­tro­phe re­sponse means get­ting aid work­ers and civil­ians back on­line. But could the tools used to cre­ate emer­gency in­ter­net be used to conne

Popular Mechanics (South Africa) - - SURVIVAL ISSUE - IL­LUS­TRA­TION BY GRA­HAM MUR­DOCH BY ALEXAN­DER GE­ORGE

SATEL­LITES HOW IT WORKS

In­stead of trav­el­ling through tow­ers, which are an­ten­nas con­nected to fi­bre-op­tic ca­bles in the ground, data comes from low-earth-or­bit satel­lites that are cal­i­brated to ro­tate with Earth and hold po­si­tion above the re­gion they serve. Right now com­pa­nies such as Hugh­es­net and Exede use the tech­nol­ogy to sell in­ter­net to peo­ple who live be­yond MTN or Vo­da­com’s reach. Other than the dishes and hard­ware you need on the ground, the satel­lites them­selves are im­per­vi­ous to ter­res­trial dis­as­ters. The main draw­back is sig­nal at­ten­u­a­tion. When a trans­mis­sion has to go from that high up all the way down to Earth, it loses data along the way and has to re­send the sig­nal un­til ev­ery­thing reaches the re­cip­i­ent. So data trans­fer is slow. As­sum­ing no rain or even clouds are block­ing it, the con­nec­tion feels like us­ing a 56K mo­dem. That’s good for an air­port or hos­pi­tal that needs to com­mu­ni­cate and run ba­sic soft­ware but un­suit­able for things like video stream­ing and large-file trans­fer.

VER­DICT

Satel­lites are ex­tremely ex­pen­sive to launch, so it’ll be a while be­fore they re­place, or even sup­ple­ment, tow­ers. “There’s a lot that can be done with caching and buffer­ing, us­ing ma­chine learn­ing to plan what needs to be stored on what servers,” says Kerri Ca­hoy, an as­so­ciate pro­fes­sor at MIT and NASA re­searcher who spe­cialises in space­craft communications and satel­lites. “It’s pos­si­ble to do bet­ter.”

HOW IT WORKS

De­vices such as the Air­bus Zephyr, Face­book’s Aquila drone, and the Pro­ject Loon bal­loons use so­lar pan­els to power an­ten­nas and com­put­ers that am­plify the sig­nal from func­tion­ing ter­res­trial cell tow­ers. Com­pared to the labour, time and civil en­gi­neer­ing re­quired to build a new cell tower, some­thing like Pro­ject Loon is cheap to de­ploy. Once launched, a bal­loon ba­si­cally flies it­self, pro­vid­ing LTE to nearly 5 000 square kilo­me­tres. But even Pro­ject Loon’s record for stay­ing in the air is rel­a­tively short: 190 days – not as re­li­able as a cell tower or fi­bre ca­bles. Con­nect­ing a ru­ral area re­quires a con­sis­tent con­nec­tion, and some­times-on in­ter­net won’t cut it for pay­ing cus­tomers. That points to a larger is­sue with get­ting in­ter­net to re­mote places. “The way these tow­ers work is: are there enough users to pay it off?” says Sal Can­dido, the head soft­ware en­gi­neer for Pro­ject Loon. “The car­ri­ers have to get a re­turn on their in­vest­ment.”

VER­DICT

Bril­liant ad­vance­ment for dis­as­ters, not re­li­able enough to re­place cell tow­ers. Yet.

ROOFTOP DIY HOW IT WORKS

Off-the-shelf routers and an­ten­nas set high on rooftops work like small cell tow­ers but with a much shorter range. Or­gan­i­sa­tions like the Detroit Com­mu­nity Tech­nol­ogy Pro­ject in Detroit or the Red Hook Ini­tia­tive in New York City use the de­vices and their band­width or satel­lite con­nec­tion to build their own net­works. This can give in­ter­net ac­cess to peo­ple who can’t af­ford home Wi-fi or a phone data plan or, in emer­gency re­sponse, pro­vide in­ter­net ser­vice while you wait for the ser­vice provider to re­pair cell tow­ers. Un­like cell tow­ers, how­ever, these net­works can’t han­dle many peo­ple. Af­ter Hur­ri­cane Sandy hit New York City in 2012, the Red Hook Ini­tia­tive’s net­work could pro­vide in­ter­net to only 150 users at once.

VER­DICT

A re­li­able, if lim­ited, al­ter­na­tive to air­borne in­ter­net. We also ap­plaud any home­made pro­ject like this.

FLY­ING AN­TEN­NAS

Air­bus Zephyr

Pro­ject Loon

APRIL 2018

Aquila drone

A rooftop an­tenna

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